Creating an associate or staff member opinion poll that is valid and functional can be a time consuming project for law firms. A new book provides access to 20 diagnostic employee questionnaires that measure such things as morale, engagement and commitment. The book, Employee Opinion Questionnaires: 20 Ready-to-Use Surveys That Work is authored by Paul M. Connolly, a professional test and survey designer (Pfeiffer/A Wiley Imprint, $95).   The book also contains norms for 30 of the most important and common employee survey questions based on a database of 80,000 responses in 170 organizations. The book comes with the surveys on CD.